This invention relates to a paperboard food carton formed from a unitary paperboard blank, the carton being of the type having a hinged top or cover. Many food products, such as hamburgers and the like are packaged in paperboard cartons and sold by so-called fast food restaurants. In the case of hot sandwiches with condiments (roast beef, corned beef, hamburger, turkey and the like) the personnel at the fast food restaurant may place a lower bread bun in the bottom tray or bottom half of the opened carton. A hot hamburger patty is then placed on top of the lower bun. Usually, toppings or condiments such as diced onions, onion slices, tomato slices, lettuce, pickle slices, etc. are placed on top of the patty, the upper bread bun placed on top of the toppings and the carton closed. Alternatively, the hamburger may be completely made, with the toppings, and then placed in the food carton. The carton is then either immediately handed to the customer, or the carton may be placed in a holding storage rack, or placed within a larger container such as a bag in those cases wherein the customer orders the food product through a so-called drive-thru window in the fast food restaurant.
Particularly in those cases wherein the hamburger and carton which contain it are placed in a storage area, or are placed in a larger container which is adapted to carry other food products, such as french fries and soft drinks, there can exist an appreciable length of time between the making of the hamburger and the opening of the carton and consumption of the hamburger by the customer. This length of time results in a cooling of the hamburger and warming of the condiments making them soggy. This cooling and warming effect is accelerated by the intimate, touching contact of the top of the hot hamburger with the toppings, the toppings usually being at ambient temperature or lower. Thus, as soon as the toppings are put on the hot hamburger, there is an immediate transfer of heat from the hot hamburger to the toppings, thereby diminishing the temperature and the taste quality of the hamburger and changing the texture of either the hamburger, roast beef, or other primary meat product, or the texture of the condiments, or both.